Toshiba Memory Corporation Semiconductor Handling Precautions and Requests

Transcription

1 Toshiba Memory Corporation Semiconductor Handling Precautions and Requests Ver.2 July 2018

2 Table of contents Handling Precautions and Requests Chapter 1 Usage Notes for Semiconductor Products... 4 Chapter 2 Safety Precautions General Precautions Regarding Semiconductor Products... 6 Chapter 3 General Usage Considerations From Incoming to Shipping Electrostatic Discharge (ESD) Work Environment Control Controlling Operation Transportation Vibration, Impact and Stress Storage General Packaged Products Moisture-Proof Packing Design Absolute Maximum Ratings Operating Range Derating Unused Pins Latch-Up Input/Output Protection Load Capacitance Thermal Design Mechanical Stress Interfacing Decoupling External Noise Electromagnetic Interference Peripheral Circuits Safety Standards Other

3 Table of contents 3-4. Inspection, Testing and Evaluation Grounding Inspection Sequence Mounting Lead Forming Soldering Temperature Profile Flux Cleaning No Cleaning Socket Mounting Chips Mounting Circuit Board Coating Heat Sinks Tightening Torque Repeated Semiconductor-Product Mounting and Usage Operating Environment Temperature Humidity Corrosive Gases Radioactive and Cosmic Rays Strong Electrical and Magnetic Fields Interference from Light Dust and Oil Smoke and Ignition Disposal...39 Appendix 1. Derating Concepts and Methods...40

4 Chapter 1 Usage Notes for Semiconductor Products Even though we make a continuous effort to improve the quality and reliability of our products, semiconductor products can malfunction or fail. When using our semiconductor products (hereinafter called Product ), please consider safety design for the customer s hardware, software, and systems and their responsibilities to prevent loss of human life, bodily injury or damage to property due to a malfunction or failure of Product. Before starting designing or using the Product, customers must read and comply with the latest information of the Product (this document, specifications, data sheets, application notes, and technical references for the Product) and the product instruction manuals and operation manuals for the application in which the Product will be used. When using any technical contents, including product data, diagrams, and tables and information including program code, algorithms, and sample application circuits described in the above documents, for customers products, customers must thoroughly evaluate their own products independently as well as whole systems and determine the applicability of the information in relation to the customers responsibilities.

5 Chapter 2 Safety Precautions This section lists important precautions which users of semiconductor products should observe in order to avoid injury to the user or anyone else and damage to property, and to ensure safe and correct use of our products. Please be sure that you understand the meanings of the labels and graphic symbols described below before you move on to the detailed descriptions of the precautions, and comply with the precautions stated. [Explanation of Labels] Indicates a hazardous situation which, if not avoided, will result in death or serious injury 1. Indicates a hazardous situation which, if not avoided, could result in death or serious injury 1. Indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate injury 2. Indicates practices that may cause property damage 3 and other problems, but not personal injury. 1. Serious injury includes blindness, wounds, burns (low and high temperature), electric shock, fractures, and poisoning, etc. with long-lasting effects or that require hospitalization and/or long-term hospital visits for treatment. 2. Minor or moderate injury includes wounds, burns, electric shock, etc. not requiring hospitalization and/or long-term hospital visits for treatment. 3. Property damage means damage to customer or third party machines and equipment. [Explanation of Graphic Symbols] Prohibited Indicates prohibited actions. Instructions Indicates actions that must be undertaken for safety purposes.

6 Chapter 2 Safety Precautions 2-1. General Precautions Regarding Semiconductor Products Prohibited Prohibited Prohibited The absolute maximum ratings of a semiconductor device are a set of ratings that must not be exceeded, even for a moment. Do not exceed any of these ratings. Exceeding the rating(s) may cause the device breakdown, damage or deterioration, and may result injury by explosion or combustion. Do not insert devices in the wrong orientation or incorrectly. Make sure that the positive and negative terminals of power supplies are connected properly. Otherwise, the current or power consumption may exceed the absolute maximum rating, and exceeding the rating(s) may cause the device breakdown, damage or deterioration, and may result injury by explosion or combustion. In addition, do not use any device that is applied the current with inserting in the wrong orientation or incorrectly even just one time. Do not touch the semiconductor product and its heat sink while the semiconductor product is on or immediately after it has been turned off. Devices and Heat sinks become hot. Contact to the heat sink may result in a burn. Prohibited Do not touch the lead tips of a device. Some devices have leads with sharp tips. Contact to sharp tips may result in a puncture wound. Instructions Check that there is no electrical leakage before grounding measuring equipment or a solder iron. Electrical leakage may cause electric shock or the device you are testing or soldering to electrically break down. Instructions On the evaluation, inspection or test, be sure to connect the test equipment s electrodes or probes to the pins of the device before turning the power on. When you have finished, discharge any electrical charge remaining in the device. Failure to do so may cause electric shock, resulting in injury. Instructions Always wear safety glasses when cutting the leads of a device with clippers or a similar tool. Failure to do so may result in eye damage from the small shavings that fly off the cut ends.

7 This section provides information that will help you gain a better understanding of semiconductor products so as to ensure product safety, quality and reliability From Incoming to Shipping Electrostatic Discharge (ESD) Semiconductor products are very sensitive to electrostatic charges. If a high voltage electricity caused by electrostatic discharge flows through a semiconductor product, the product may be destroyed. Especially, for MOS type semiconductors, as little as several tens of voltage can destroy the devices. Humans feel a discharge of two to three kv, which indicates how only a trace amount of voltage can destroy semiconductor products. Therefore, countermeasures against electrostatic charges are required. When handling semiconductor products, be sure that the environment is protected against static electricity. Operators should wear anti-static clothing, anti-static shoes, and a wrist strap. In addition, containers and other objects that come in direct contact with semiconductor products should be made of materials that do not produce static electricity that would cause damage. Control anti-static equipment at all times to ensure that it works correctly. Please follow the precautions below. This is particularly important for those semiconductor products marked Be careful of ESDS*. *: ElectroStatic Discharge Sensitive products

8 Work Environment Control (1) When humidity decreases, static electricity readily occurs due to friction. Taking into consideration the fact that moisture-proof-packed products absorb moisture after unpacking, the advisable relative humidity is 40 to 70%. (2) Be sure that all equipment such as jigs and tools installed in the work area are grounded. (3) Place a conductive mat over the floor of the work area or take other measure to ensure that the floor is protected against static electricity and is grounded to the earth. (Resistance between the floor surface and ground: 1 x 10 9 Ω or less) (4) Place a conductive mat over the surface of worktables to ensure that the tables are grounded. (Resistance between surface and ground: 7.5 x 10 5 to 1 x 10 9 Ω) Do not construct worktable surfaces of metallic materials. Metallic materials are low in resistance, allowing rapid discharge when a charged semiconductor product comes in contact with them directly. (5) Observe the following when using automated equipment: (a) When picking up a semiconductor product with a vacuum, use conductive rubber in sections which come into contact with the product surface to protect against electrostatic charge. (b) Avoid friction on the semiconductor-product surface to the extent possible. If rubbing is unavoidable due to the product s mechanical structure, minimize the friction plane or use material with a small friction coefficient and low electrical resistance. Also, prevent electrostatic charge by using an ionizer. (c) Use a material which dissipates static electricity in sections which come in contact with semiconductor-product leads or terminals. (d) Ensure that no statically charged bodies (such as work clothes or the human body) come in contact with the semiconductor products. (e) Use a tape carrier that employs a low-resistance material on sections that come in contact with electrical machinery. (f) Make sure that jigs and tools used in the manufacturing process do not touch the semiconductor products.

9 (g) In processing associated with package electrostatic charge, use an ionizer to neutralize the ions in the ambient environment. (6) Ensure that the work chairs are protected by a conductive cover and grounded to the floor by conductive castors. (Resistance between seat surface and ground: 1 x Ω or less) (7) Install anti-static mats on storage shelf surfaces and ground the mat surface. (Resistance between surface and ground: 7.5 x 10 5 to 1 x 10 9 Ω) (8) For semiconductor-product transport and temporary storage, use containers (boxes, jigs or bags) that are made of a material which does not produce static electricity that could damage the semiconductor product. (9) Make sure that cart surfaces which come in contact with product packaging are made of materials which conduct static electricity, and ground the cart surfaces to the floor surface using conductive castors. (10) In static electricity control areas, install anti-static dedicated ground wires. Use a transmission line circuit ground wire [Type D or above], or a trunk line ground wire. In addition, separate and ground the various devices individually. (11) Make sure that CRT displays in the work area are protected against static charge by employing a filter, for example. Avoid turning displays on and off to the extent possible. Neglecting to do so can cause electrostatic induction in semiconductor products. (12) Periodically measure the charged potential of semiconductor products, systems and fixtures located in the work area to ensure that the area is free of any charge.

10 Controlling Operation (1) Operators must wear anti-static clothing and anti-static shoes (or a toe or heal strap). (2) Operators must wear a wrist strap grounded to earth via a resistor. (Resistance between surface and earth when worn: 7.5 x 10 5 to 3.5 x 10 7 Ω) (3) Soldering irons must be grounded from the iron tip to earth, and must be used at low voltages (6 to 24 V). (4) If the tweezers you use are likely to touch the semiconductor-product terminals, use anti-static tweezers. Do not use metallic tweezers since they are low in resistance and may cause rapid discharge when a charged semiconductor product comes in contact with them. When using a vacuum tweezers, attach a conductive chucking pat to the tip, and connect it to a dedicated anti-static ground. In addition, follow the manufacturer s methods of use and maintenance. (5) Do not place semiconductor products or their containers near sources of strong electrical fields (such as above a CRT). (6) Place boards with mounted semiconductor products in anti-static board containers separated from one another, and do not stack them directly on top of one another. Stacking them directly on top of one another may cause frictional charge or discharge. (7) Ensure, to the extent possible, that any articles (such as clipboards) which are brought to a static electricity control area are constructed of anti-static materials. (8) When the human body is to come in direct contact with a semiconductor product, wear anti-static finger covers or gloves.

11 (9) The material of equipment safety covers located near semiconductor products should have a resistance value of 1 x 10 9 Ω or less. (10) If a wrist strap cannot be used and there is a possibility of imparting friction to semiconductor products, use an ionizer. (11) The transport film used in tape carrier products is manufactured from materials in which static electricity readily builds up. When using these products, use an ionizer to prevent the film from being charged. Also, to ensure than no static electricity will be applied to the copper foil area, take measures to prevent electrostatic discharge failure of peripheral equipment Transportation (1) Handle exterior fiberboard boxes carefully. Note that a physical shock or dropping the product can cause product damage. (2) Handle interior boxes with extra care. If you drop the box, products may fly out of a magazine or a tray inside, deforming their leads. (3) Protect products from water. Do not let products become wet from rain or snow while carrying them. (4) Minimize mechanical vibration and shock during transportation. Especially for wafer shipping, take special care not to cause vibrations and shock during transportation.

12 Vibration, Impact and Stress Handle individual or packed semiconductor products with care. Dropping or applying impact to semiconductor products or packaging causes semiconductorproduct damage. Ensure that they are not subjected to mechanical vibration or impact to the extent possible. Hollow canister-type and ceramic sealed semiconductor products contain unsecured wires, making them more susceptible to vibration and impact than plastic sealed semiconductor products. When the body or a connecting part of a semiconductor product is subjected to vibration, impact or stress in actual equipment, bonding fault or device destruction may result. Therefore, be sure to keep this in mind at the time of structural design. If a semiconductor product is subject to especially strong vibration, impact or stress, the package or chip may crack. If stress is applied to a semiconductor chip through the package, changes in the resistance of the chip may result due to piezoelectric effects, resulting in fluctuation in element characteristics. Furthermore, if a stress that does not instantly result in damage is applied continually for a long period of time, product deformation may result, causing defects such as disconnection or element failure. Thus, at the time of structural design, carefully consider vibration, impact and stress.

13 3-2. Storage General Packaged Products (1) Avoid storage locations where semiconductor products may be exposed to water (wet, rain, dew condensation, etc.) or direct sunlight. (2) Follow the precautions printed on the packing label for transportation and storage. (3) Also refer to Transportation for transporting packed products. (4) Keep the storage location at temperature and relative humidity within a range of 5 C to 35 C and 45% to 75%, respectively. (5) Do not store the products in locations with poisonous gases (especially corrosive gases) and/or in dusty conditions. (6) Store the products in locations with minimal temperature fluctuations. Rapid temperature changes during storage can cause dew condensation, resulting in lead oxidation or corrosion, which will deteriorate the solderability of leads. (7) When restoring semiconductor products after removal from their packing, use anti-static containers. (8) Do not allow loads to be applied directly to semiconductor products while they are in storage. (9) If semiconductor products have been stored for more than two years under normal storage conditions, it is recommended that you check the leads for ease of soldering prior to use.

14 Moisture-Proof Packing Moisture-proof packing should be used while taking into careful consideration the handling methods specified for each packing type. If the specified procedures are not followed, the quality and reliability of the semiconductor products may be deteriorated. This section describes the general precautions for handling moisture-proof packing. Since the details may differ depending on the semiconductor products, please follow the specific delivery specification for handling packed products. If no delivery specification is designated, please seek guidance from our sales contact Moisture-Proof Packing General Precautions Follow the precautions printed on the packing label for transportation and storage. To transport packed products, also refer to Transportation. For chip products, follow the respective specifications. (1) Do not toss or drop product packing. The aluminum laminated bag may be damaged, resulting in a loss in airtightness. (2) Follow the specific delivery specification for storage environment and storage temperature. If no delivery specification is designated, please seek guidance from our sales contact.

15 (3) If the storage period has been exceeded, or if the 30% humidity indicator is pink when the package is opened, remove any moisture under the conditions described in the table below. The effective usage period without moisture removal after the packing has been opened and the product has been stored at 5 C to 30 C and relative humidity at 70% or less is listed on the moistureproof package. If the effective usage period has been exceeded, or if the packing has been stored in a high-humidity environment or an environment that produces dew condensation, remove any existing moisture. (4) When removing the moisture from semiconductor products, protect the products from breakdown from static electricity. (5) Moisture indicators (for your reference) Moisture indicators detect the approximate ambient humidity level at a standard temperature of 25 C. Figure shows a 1-point indicator. Silicagel package Humidity indicator 1-point indicator Figure Humidity Indicator (6) Do not allow loads to be applied directly to semiconductor products while they are in storage.

16 Table Feasibility and Conditions of Moisture Removal by Packaging Forms of Semiconductor Products Semiconductor- Product Packing Type Feasibility and Conditions for Moisture Removal Since moisture-proof packing bags are not heat resistant, do not perform the baking process on them as they are. Tray Type (1). For heat resistant trays (when there is a Heatproof or temperature indication) Please observe the following conditions regarding the baking process. 1 Remove the tray from the moisture-proof packing bag. 2 Perform the baking process according to the instructions written on the moisture-proof bag. (2). For trays that are not heat resistant (when there is not a Heatproof or temperature indication) Please observe the following conditions regarding the baking process. 1 Remove the tray from the moisture-proof packing bag. 2 Transfer the product to another heat-resistant container with static electricity measures. 3 Perform the baking process according to the instructions written on the moisture-proof bag. Since moisture-proof packing bags are not heat resistant, do not perform the baking process on them as they are. Magazine Type Taping Type Please observe the following conditions regarding the baking process. 1 Remove the magazine from the moisture-proof packing bag. 2 Transfer the product to another heat-resistant container with static electricity measures. 3 Perform the baking process according to the instructions written on the moisture-proof bag. Since moisture-proof packing bags are not heat resistant, do not perform the baking process on them as they are. Taping products are not heat-resistant with respect to all packing components (embossed tape, cover tape, and reel), so do not perform the baking process as they are. (Some products can be baked as they are, but for baking conditions please follow the instructions written on the moisture-proof bags.) Please observe the following conditions regarding the baking process. 1 Remove the reel from the moisture-proof packing bag. 2 Transfer the product to another heat-resistant container with static electricity measures. 3 Perform the baking process according to the instructions written on the moisture-proof bag.

17 3-3. Design To achieve the reliability required by an electronic device or system, it is important not only to use the semiconductor product in accordance with specified absolute maximum ratings and operating ranges, but also to consider the environment in which the equipment will be used, including factors such as the ambient temperature, humidity, vibration, impact, stress, transient noise and current surges, as well as mounting conditions which affect semiconductor-product reliability. This section describes general design precautions. Be sure to refer to the respective technical datasheets of each product at the time of design Absolute Maximum Ratings Prohibited The absolute maximum ratings of a semiconductor device are a set of ratings that must not be exceeded, even for a moment. Do not exceed any of these ratings. Exceeding the rating(s) may cause the device breakdown, damage or deterioration, and may result injury by explosion or combustion. If the voltage or current on any pin exceeds the absolute maximum rating, the overvoltage or overcurrent causes the semiconductor product s internal circuitry to deteriorate. In extreme cases, heat generated in internal circuitry can fuse wiring or cause the semiconductor chip to break down. If the storage or operating temperature exceeds the absolute maximum rating, the semiconductor-product internal circuitry may deteriorate and the bonded areas may open or the package airtightness may deteriorate due to the differences between the thermal expansion coefficients of the materials from which the semiconductor product is constructed. Although absolute maximum ratings differ from product to product, they essentially concern the voltage and current at each pin, the allowable power dissipation, the connecting area temperatures, and storage temperatures. Note that the term maximum rating which appears in the respective technical datasheets and the like refers to absolute maximum rating.

18 Operating Range The operating range is the range of conditions necessary for the semiconductor product to operate as specified in the respective technical datasheets. Care must be exercised in the design of the equipment. If a semiconductor product is used under conditions that do not exceed absolute maximum ratings but exceed the operating range, the specifications related to semiconductor-product operation and electrical characteristics may not be met, resulting in a decrease in reliability. If greater reliability is required, derate the semiconductor product s operating ranges for voltage, current, power and temperature before use Derating The term derating refers to ensuring greater semiconductor-product reliability by setting operating ranges reduced from rated values and taking into consideration factors such as current surges and noise. While derating generally applies to electrical stresses such as voltage, current and power, and environmental stresses such as ambient temperature and humidity. Power devices in particular have relatively large self-heating, therefore the level of junction temperature (Tj) derating greatly affects reliability. For your reference, details are provided in the appendix. Be sure to read the appendix carefully.

19 Unused Pins If unused pins are left open, some semiconductor products exhibit input instability, resulting in faulty operation such as a sudden increase in current consumption. In addition, if unused output pins on a semiconductor product are connected to the power supply, GND or other output pin, the IC may malfunction or break down. Since the treatment of unused input and output pins differs for each product and pin, please follow the explanation in the respective technical datasheets. If no treatment method is described in the respective technical datasheet, please seek guidance from our sales contact. CMOS logic IC inputs, for example, have extremely high impedance. If an input pin is left open, it can readily pick up noise and become unstable. In this case, if the input reaches an intermediate level, both the P-channel and N-channel transistors will become conductive, allowing unnecessary power supply current to flow. It is therefore necessary to ensure that the unused input gates of a semiconductor product are connected to the power supply pin or ground (GND) pin of the same product. For treatment of heat sink pins, refer to the respective technical datasheets Latch-Up Semiconductor products sometimes transition to an inherent condition referred to as latchup. This condition mainly occurs in CMOS semiconductor products. This happens when a parasitic PN-PN junction (thyristor structure) built in the semiconductor product itself is turned on, causing a large current to flow between the power supply voltage and GND, eventually causing the semiconductor product to break down. Latch-up occurs when the voltage impressed on an input or output pin exceeds the rated value, causing a large current to flow in the internal element, or when the voltage impressed on the power supply voltage pin exceeds its rated value, forcing the internal element to breakdown. Once the element falls into the latch-up state, even though the excess voltage may have been applied only for an instant, the large current continues to flow between the power supply voltage and GND, potentially causing product explosion or combustion. To avoid this problem, observe the following:

20 (1) Do not allow the voltage levels on the input and output pins to rise above the power supply voltage or decrease below GND. Consider the timing during power supply activation as well. (2) Do not allow any abnormal noises to be applied to the semiconductor product. (3) Set the electrical potential of unused input pins to the power supply voltage or GND. (4) Do not create an output short Input/Output Protection Wired-logic configurations in which outputs are connected together directly cannot be used since the outputs short-circuit with the configurations. Outputs should, of course, never be connected to the power supply voltage or GND. In addition, products with tri-state outputs can undergo product deterioration if a shorted output current continues for a long period of time. Design the circuit so that the tri-state outputs will not be enabled simultaneously Load Capacitance Certain semiconductor products exhibit an increase in delay times and a large charging and discharging current if a large load capacitance is connected, resulting in noise. In addition, since outputs are shorted for a long period of time, wiring can become fused. Use the load capacitance recommended for each product Thermal Design The failure rate of semiconductor products largely increases as the operating temperatures increase. As shown in Figure 3-3-1, the thermal stress applied to semiconductor-product internal circuitry is the sum of the ambient temperature and the temperature rise caused by the power consumption of the semiconductor product.

21 Please refer to the considerations for thermal design in the respective technical datasheets. To achieve even higher reliability, take into consideration the following thermal design points: (1) Conduct studies to ensure that the ambient temperature (Ta) is maintained as low as possible, avoiding the effects of heat generation from the surrounding area. (2) If the semiconductor product s dynamic power consumption is relatively large, conduct studies regarding use of forced air-cooling, circuit board composed of low thermal resistance material, and heat sinks. Such measures can lower the thermal resistance of the package. (3) Derate the semiconductor product s absolute maximum ratings to minimize thermal stress from power consumption. Θja = Θjc + Θca Θja = (Tj - Ta)/P Θjc = (Tj - Tc)/P Θca = (Tc - Ta)/P Θja: Thermal resistance between junction and ambient air ( C/W) Θjc: Thermal resistance between junction and package surface, or internal thermal resistance ( C/W) Θca: Thermal resistance between package surface and ambient air, or external thermal resistance ( C/W) Tj: Junction temperature or chip temperature ( C) Tc: Package surface temperature or case temperature ( C) Ta: Ambient temperature ( C) P: Power consumption (W) Figure Thermal Resistance of Package

22 Mechanical Stress Applying mechanical stress to packages can degrade the adhesion strength of the packages and allow moisture and contaminants to seep into the packages, thereby degrading the quality of the semiconductor products Interfacing When connecting semiconductor products with different input and output voltage levels, make sure that the input voltage (VIL/VIH) and output voltage (VOL/VOH) levels match. Otherwise, the semiconductor products may malfunction. To transfer data between two pins, make the input setup/hold times and the output transmission delay consistent. Otherwise, the semiconductor products may malfunction. In addition, when connecting semiconductor products with different power supply voltages, such as in a dual power supply system, semiconductor-product breakdown may result if the power-on and power-off sequences are incorrect. For semiconductor-product interface details, refer to the respective technical datasheets. In addition, if you have any questions about interfacing, contact your nearest Toshiba office or distributor.

23 Decoupling Spike currents generated during switching can cause power supply voltage and GND voltage levels to fluctuate, causing ringing in the output waveform or a delay in the response speed. (The power supply and GND wiring impedance is normally 50 to 100 Ω.) For this reason, the impedance of the power supply lines with respect to high frequencies must be kept low. Specifically, this is ideally accomplished by routing thick and short power supply and GND lines and by inserting decoupling capacitors (of approximately 0.01 to 1 μf) as high-frequency filters between the power supply and GND into each required location on the circuit board. For low-frequency filtering, it is appropriate to insert a 10 to 100 μf capacitor in each circuit board. However, conversely if the capacitance is excessively large (such as 1000 μf), latch-up may result. An appropriate capacitance value is therefore required. On the other hand, in the case of high-speed logic ICs, noise is caused by reflection, crosstalk or common power supply impedance. Reflections cause increased signal delay, ringing, overshoot and undershoot, thereby reducing the semiconductor product s noise margin. One effective wiring measure for preventing reflections is to reduce the wiring length by increasing the mounting density so as to lower the wiring inductance (L) and capacitance (C). This measure, however, also requires consideration with regard to crosstalk between wires. In actual pattern design, both of these factors must be considered External Noise When externally induced noise or surges are applied to a printed circuit board with long I/O signals or signal lines, malfunction may result, depending on the semiconductor product. Input/Output Signals

24 To protect against noise, protective measures against surges must be taken such as lowering the impedance of the signal line or inserting a noise-canceling circuit. For details of required protection, refer to the respective technical datasheets Electromagnetic Interference Radio and TV reception problems have increased in recent years as a result of increased electromagnetic interference radiated from electrical and electronic equipment. To use radio waves effectively and to maintain the quality of radio communications, each country has defined limitations for the amount of electromagnetic interference which can be generated by designated devices. The types of electromagnetic interference include noise propagated through power supply and telephone lines, and noise from direct electromagnetic waves radiated from equipment. Different measurement methods and corrective actions are used for each type. Difficulties in countering electromagnetic interference derive from the fact that there is no means for calculating at the design stage the strength of the electromagnetic waves produced from each component in a piece of equipment. As a result, it is after the prototype equipment has been completed that measurements are taken using dedicated instruments to determine for the first time the strength of the electromagnetic interference. Yet it is possible during system design to incorporate measures for the prevention of electromagnetic interference, which can facilitate corrective action after design completion. One effective method, for example, is to design the product with several shielding options, and then select the optimum shielding method based on the results of the measurements subsequently taken Peripheral Circuits In many cases semiconductor products are used with peripheral circuits and components. The input and output signal voltages and currents in these circuits must be designed to match the specifications of the semiconductor product, taking into consideration the factors below. (1) Input voltages and currents that are not appropriate with respect to the input pins may cause malfunction. Some semiconductor products contain pull-up or pull-down resistors, depending on specifications. Design your system taking into account the required voltage and current.

25 (2) The output pins on a semiconductor product have a predetermined external circuit drive capability. If a drive capability exceeding this value is required, either insert a compensating circuit or take that fact into account when selecting components for use in external circuits Safety Standards Each country and region has established safety standards which must be observed. These safety standards sometimes include requirements for quality certification systems and insulation design standards. The safety standards of the respective countries and regions must be taken fully into account to ensure compliant semiconductor-product selection and design Other (1) When designing a system, incorporate fail-safe and other measures according to system application. In addition, debug the system under actual mounting conditions. (2) If a plastic package semiconductor product is placed in a strong electric field, surface leakage may occur due to charge-up, resulting in malfunction. When using such a product in a strong electric field, take measures by, for example, protecting the package surface with a conductive shield. (3) With some memory devices and microcomputers, attention is required at power on or reset release. To ensure that your design is appropriate for a semiconductor product, refer to the respective technical datasheets. (4) Do not shut off the power supply while rewriting flash memory. High electric fields generated inside the package due to the power shutting off can destroy its internal elements. (5) Design the casing so as to ensure that no conductive material (such as a metal pin) can drop from an external source onto a terminal of a mounted semiconductor product, causing a short.

26 3-4. Inspection, Testing and Evaluation Grounding Instructions Check that there is no electrical leakage before grounding measuring equipment or a solder iron. Electrical leakage may cause electric shock or the semiconductor product you are testing or soldering to electrically break down Inspection Sequence Prohibited Instructions Do not insert devices in the wrong orientation or incorrectly. Make sure that the positive and negative terminals of power supplies are connected properly. Otherwise, the current or power consumption may exceed the absolute maximum rating, and exceeding the rating(s) may cause the semiconductor-product breakdown, damage or deterioration, and may result injury by explosion or combustion. In addition, do not use any semiconductor product that is applied the current with inserting in the wrong orientation or incorrectly even just one time. On the evaluation, inspection or test, be sure to connect the test equipment s electrodes or probes to the pins of the semiconductor product before turning the power on. When you have finished, discharge any electrical charge remaining in the semiconductor product. Failure to do so may cause electric shock, resulting in injury. (1) Apply voltage to the semiconductor product after inserting it into the test jig. At this time, observe the power supply activation or shutdown standards, if existent. (2) After test completion, be sure that the voltage applied to the semiconductor product is off before removing the semiconductor product from the test jig. Removing the semiconductor product with the power supply on can cause semiconductor-products deterioration or breakdown.

27 (3) Make sure that no surge voltages from the measuring equipment are applied to the semiconductor product. (4) The chips in tape carrier packages (TCPs) are LSI chips and therefore exposed. During inspection, be careful not to crack or scratch the chip. Electrical contact may also cause chip failure. Therefore make sure that nothing comes into electrical contact with the chip. (5) Note that X-ray radiation can change product characteristics during X-ray inspection Mounting There are two types of semiconductor-product packages: lead insertion and surface mount. The items that affect reliability during circuit board mounting include contamination by flux and thermal stress during the soldering process. With surface-mount packages in particular, the most significant problem is thermal stress from solder reflow, when the entire package is subjected to heat. In addition, the mounting method differs according to factors such as chip size and frame design, even for the same package type. For more details, please refer to the technical datasheet for each semiconductor product. When a location such as a soldered area, connecting area or top surface of a product is subjected to vibration, impact or stress in actual equipment, bonding fault or device destruction may result. Therefore, be sure to keep this in mind at the time of mounting. If a product is subject to especially strong vibration, impact or stress, the package or chip may crack. Thus, at the time of mounting, carefully consider vibration, impact and stress.

28 Lead Forming Prohibited Do not touch the lead tips of a device. Some devices have leads with sharp tips. Contact to sharp tips may result in a puncture wound. Instructions Always wear safety glasses when cutting the leads of a device with clippers or a similar tool. Failure to do so may result in eye damage from the small shavings that fly off the cut ends. Semiconductor products sometimes undergo a process in which the leads are cut and formed before the products are installed on a printed circuit board. If abnormal stress is applied to the interior of a semiconductor product during this process, mechanical breakdown or reliability deterioration may result. This is attributable mainly to the relative stress applied between the semiconductor product itself and the lead, and can result in internal lead damage, adhesive property deterioration and sealant breakdown. Observe the following precautions during the lead-forming process. (This does not apply to surface-mount semiconductor products.) (1) Lead insertion hole intervals on the printed circuit board should be designed using the same dimension standard as that for the lead interval of the semiconductor product. (2) If the lead insertion hole intervals on the printed circuit board do not match the lead interval of the semiconductor product, do not forcibly insert the semiconductor product.

29 (3) For the minimum dimension between a semiconductor product and printed circuit board, refer to the respective technical datasheets. When necessary, create space when forming the semiconductor product s leads. Do not use the spacers for raising semiconductor products above the surface of the printed circuit board during soldering. These spacers may continue to expand due to heat even after the solder has solidified, sometimes applying a great amount of stress to the semiconductor product. (4) Observe the following when forming the leads of a semiconductor product: (a) When bending a lead, secure the lead at the end of the bending section near the package to ensure that mechanical stress is not applied to the semiconductor product. Also, do not repeatedly bend or stretch a lead at the same location. (b) Do not damage the lead during lead forming. (c) Please follow the precautions defined in the respective technical datasheets.

30 Soldering Temperature Profile Perform soldering following the methods and conditions described in the respective technical datasheets for the semiconductor product used. The soldering method, temperature and time may be restricted, depending on the product. All soldering temperature profiles and conditions described in the mounting methods below are representative. The profiles and conditions vary from product to product. Therefore, mount the product after first confirming the information described in the respective technical datasheets and databooks with the customer. Reflow soldering and flow soldering must not be combined when performed. For details regarding special soldering including lead(pb) soldering, please contact your nearest Toshiba office or distributor Using a Soldering Iron (Typical Example) Complete soldering within 10 seconds for soldering iron temperatures of up to 260 C, or within 3 seconds for soldering iron temperatures of up to 350 C Using Infrared Reflow (Typical Example) (1) It is recommended the top and bottom heating method with long or medium infrared rays. (2) The maximum package surface temperature is 260 C. The duration where package surface temperature is 255 C or more must be no longer than 30 seconds. (3) Refer to Figure for an example of a temperature profile. within 30 s Figure Example of Temperature Profile

31 This profile is based on the product s maximum heat resistance guaranteed value. Set the preheat temperature/heating temperature to the optimum temperature corresponding to the solder paste type used by the customer within the above-described profile Using Hot Air Reflow (Typical Example) The maximum package surface temperature is 260 C. The duration where package surface temperature is 255 C or more must be no longer than 30 seconds. For an example of a temperature profile, refer to Figure above Using Solder Flow/Dip (Typical Example) (1) Apply preheating for 60 to 120 seconds at a temperature of 150 C. (2) Perform the solder flow at a maximum temperature of 260 C for no longer than 10 seconds. (3) For insertion type packages, solder the device at the stopper part or at least 1.5 mm away from the body. (4) For surface-mount packages, since the influence of the thermal stress on the solder flow is larger than that for insertion-type packages, it is recommended to perform soldering at a lower temperature and for a shorter time than in (2).

32 Flux Cleaning (1) When cleaning circuit boards to remove flux, make sure that no reactive ions such as sodium or chlorine remain. Some organic solvents react with water to generate hydrogen chloride and other corrosive gases which can result in semiconductor-product deterioration. (2) When washing semiconductor products with water, make sure that no reactive ions such as sodium or chlorine remain particularly. (3) When washing semiconductor products, do not rub markings with a brush or with your hand while the cleansing liquid is still on the product. Doing so can rub off the markings. (4) Dip cleaning, shower cleaning and steam cleaning processes are performed based on the chemical action of a solvent. Washing should be performed at your own discretion, utilizing information from detergent manufacturers. (5) Avoid use of ultrasonic cleaning with semiconductor products in hermetically sealed ceramic packages such as a leadless chip carrier (LCC), pin grid array (PGA) or charge-coupled device (CCD). Using the ultrasonic cleaning may cause the internal wires to become disconnected due to resonance. Even if a product package allows ultrasonic cleaning, keep the duration of ultrasonic cleaning in a brief time. Long hours of ultrasonic cleaning may deteriorate the adhesion between the mold resin and frame material. The basic recommended conditions are as follows: Recommended Ultrasonic Cleaning Conditions Frequency : 27 to 29 khz Ultrasonic output : 15 W/L or less Cleaning time : 30 seconds or less

33 Suspend the printed circuit board in the solvent bath to ensure that the circuit board and semiconductor products do not come in direct contact with the ultrasonic vibrator No Cleaning It is recommended that you clean analog or high-speed semiconductor products. If such products are not cleaned, flux may cause minute leakage between leads or migration, depending on the flux grade. Be sure therefore to check cleanliness at the time of use. If you are considering no cleaning, be sure to use a flux that does not require cleaning Socket Mounting (1) When socket-mounting semiconductor products on a printed circuit board, use sockets that match the package. (2) Use sockets with contacts that have the appropriate contact pressure. If the contact pressure is insufficient, the contact may become poor when the semiconductor product is repeatedly inserted and removed. If the contact pressure is too high, the semiconductor-product leads may bend or become damaged when they are inserted into or removed from the socket. (3) When soldering sockets to the printed circuit board, use sockets designed to prevent flux from penetrating the contacts and to allow flux to be completely cleaned off. (4) Ensure that the coating agent applied to the printed circuit board for moisture-proofing does not adhere to the socket contacts. (5) If the leads are severely bent when inserted into or removed from a socket and you want to repair the leads and continue using the semiconductor product, repair the leads once only. Do not use products whose leads have been corrected multiple times.

34 (6) If external vibration will be applied to a printed circuit board with semiconductor products mounted on it, use sockets with strong contact pressure so as to prevent vibration between the semiconductor products and sockets Chips Mounting Semiconductor products delivered in chip form readily deteriorate or become damaged due to external factors in comparison with plastic-packaged products. Attention is therefore required during handling. (1) Mount semiconductor products in a properly maintained environment so that the chip will not be exposed to contaminated ambient air or other substances. (2) When handling chips, be careful not to expose the chips to static electricity. In particular, measures must be taken to prevent electrostatic breakdown during chip mounting. For this purpose, it is recommended that you mount all peripheral devices before you mount the chips. (3) Use chip mounting circuit boards (such as PCBs) that do not have any chemical residue on them (such as the chemicals used during PCB etching). (4) When mounting chips, use the method of assembly that is most suitable for achieving the appropriate electrical, thermal and mechanical characteristics of the semiconductor product used. * For chip details, refer to the relevant specification sheet Circuit Board Coating When using semiconductor products for equipment that requires high reliability or used under extreme environments (where moisture, corrosive gas or dust is present), circuit boards are sometimes coated with a moisture-proof coating. Use a coating resin causing less stress.

35 Heat Sinks Prohibited Do not touch the semiconductor product and its heat sink while the device is on or immediately after the device has been turned off. Devices and Heat sinks become hot. Contact to the heat sink may result in a burn. (1) When installing a heat sink to a semiconductor product, use the specified accessories. In addition, be careful not to apply excessive force to the semiconductor product during installation. (2) When installing a semiconductor product to a heat sink by fixing it in two or more locations, do not tighten one location to the specified torque while the rest are left not tightened. Rather, lightly tighten all locations evenly first and tighten all locations to the specified torque by rotation. (3) Drill screw holes in the heat since as specified, and smooth the surface of the semiconductor-product installation area by removing burrs and protrusions or indentations. (4) Thinly applying silicone grease between the heat sink makes semiconductor product better to improve heat conductivity compared with no grease. If you choose to apply the silicone grease, use a non-volatile type. Volatile type silicone grease can cause cracks over time, resulting in the deterioration of the heat radiation effect. (5) With plastic-packaged semiconductor products, the base oil of some silicone grease compounds penetrates the package interior, significantly reducing the lifetime of the semiconductor product. We ask therefore that you use the recommended silicone grease (Manufactured by Momentive Performance Materials Japan). If you choose to use another product, select an equivalent one.